Difficulty: Easy
Correct Answer: 90
Explanation:
Given data
Concept/Approach
Total value = x·1 + x·5 + x·10 = 16x ⇒ solve 16x = 480.
Step-by-step calculation
16x = 480 ⇒ x = 480 ÷ 16 = 30. Total notes = 3x = 3 × 30 = 90.
Common pitfalls
Adding denominations but forgetting to multiply each by the same count x.
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